What does Genesis 47:20 mean?
Joseph, as representative of the king of Egypt, has made the Pharaoh an enormously wealthy and powerful man. The people will die without the food stores that Joseph oversees. After spending all their money, the people traded their livestock (Genesis 47:13–17). Still starving, they offered their land and themselves—as servants and slaves—in trade for another year's worth of food.Joseph agrees and buys all the land of Egypt as Pharaoh's property. This implies that, in some sense, the people had previously been free and privately owned their lands and herds. They had been a free people, such as it was, but would now be entirely subject to the king of Egypt. Now they have sold their land for food. Joseph will continue this pattern, buying the people themselves as servants. Pharaoh would now own nearly everything of value in all Egypt, and he would have Joseph to thank for it.
In practice, most of the people would remain on their land and continue in their occupations. The mortgaging of their property, land, and freedom would involve giving 20 percent of all their future harvests to Pharaoh (Genesis 47:23–24).